An apparent suicide note left by a nurse at the centre of the royal hoax phone call was critical of staff at the London hospital where she worked, according to a report.

Jacintha Saldanha, 46, was found hanged at staff quarters near King Edward VII hospital in central London, just days after taking a prank phone call from 2Day FM radio presenters Mel Greig and Michael Christian.

A coronial hearing into the mother-of-two's death was told in London on Thursday morning (overnight, NZ time) that investigators found three apparent suicide notes, handwritten by Ms Saldanha.

One of those notes was addressed to her employers at the hospital and "contains criticism of staff there", The Guardian reported, adding that it had received the information from two separate sources.

Another note dealt with the hoax call made by the two Sydney radio presenters, who posed as the Queen and Prince Charles in the prank call, while the final letter detailed Ms Saldanha's requests for her funeral, the newspaper reported.

Two of the notes were found in the apartment where Ms Saldanha died and one in her belongings, and police have given Mrs Saldanha's family typed copies of the letters, The Guardian said.

Scotland Yard is investigating a number of emails which the inquest heard were relevant to the nurse's death.

Detective Chief Inspector James Harman told Coroner Fiona Wilcox that police were investigating whether telephone calls made to and from Ms Saldanha's phone in the days before her death could throw any light on her death, however the details of those emails and phone calls were not released at the brief hearing in London.

A spokeswoman for the King Edward VII hospital told The Guardian that no one in senior management knew the contents of the letters left by Ms Saldanha.

She said the hospital management "were very clear that there were no disciplinary issues in this matter".

Both the nurses involved had been offered "full support" and "it was made clear they were victims of a cruel journalistic trick," she told the newspaper.

The hospital has offered bereavement counselling for the family in Bristol, which they have decided to take up.

Ms Saldanha was found dead in her apartment three days after the DJs made the prank call.

She took the initial call and put it through to a colleague on the ward where the Duchess of Cambridge was being treated for morning sickness, who gave out information about her condition.

The hearing overnight heard that Scotland Yard detectives would be in contact with New South Wales police to interview witnesses and "put the best evidence before you" about the circumstances of the death.